000
FXUS64 KSJT 032156
AFDSJT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN ANGELO TX
356 PM CST TUE MAR 3 2015
.SHORT TERM...
(Tonight and Tomorrow)
Look for big weather changes during the next 24 hours. As a minor
upper-level disturbance moves over West Central Texas tonight, it
will bring the potential for showers and perhaps some thunderstorms.
The best chance for showers and thunderstorms will be mainly along
and north of our Interstate 20 corridor, with more favorable upper
dynamics there. In addition, low clouds will return to much of West
Central Texas overnight, as another cold front approaches from the
north. Timing of this front is critical, with respect to when winter
type precipitation will begin tomorrow. Models continue to bring the
cold front to our Interstate 20 corridor by 6 am CST tomorrow
morning. So, with that timing, we believe the winter precipitation
will not begin until tomorrow afternoon, for locations along and
north of a Mertzon, to San Angelo, to Spring Creek line. Plus, we
believe accumulation of sleet of ice will not begin until after 6 PM
CST tomorrow evening, because surface cold air advection behind the
front will not be strong enough to lower surface temperatures to or
below the freezing mark.
.LONG TERM...
(Wednesday night through next Tuesday)
Another blast of winter weather will affect all of West Central
Texas in the Wednesday night/Thursday morning time frame. Cold air
will continue to deepen across the area, with soundings showing most
areas having changed to an all winter precipitation type by
midnight. Taking a closer look at these soundings, a wedge of
warm air is seen between three-six thousand feet above the surface,
with sub-freezing air above and below this layer. This warm layer
barely reaches +3 Celsius, and the top of the saturated layer barely
touches -10/-11 Celsius (just below the dendrite growth zone). Given
this type of sounding profile, the forecast was changed to show
freezing rain as the predominant precipitation type. Some sleet
could also mix in at times, especially with any elevated convection
which develops, as the soundings show elevated instability
developing with MUCAPEs approaching 100 J/kg in the 700-450mb layer.
By Thursday afternoon, dry air will rapidly advect into the area,
allowing skies to become partly sunny from northwest to southeast
across the region. However, temperatures will be slow to recover
with most areas remaining in the 30s. Heading through the remainder
of the week and into the weekend, temperatures will continue to
moderate by 5 to 10 degrees Fahrenheit each day, with highs
approaching 60 degrees by Sunday, and remain in the 60s for the
first half of the work week.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 47 49 21 35 21 / 50 70 60 10 5
San Angelo 50 57 25 39 23 / 30 60 50 10 5
Junction 50 63 28 38 23 / 30 60 60 20 5
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
Huber/Doll